使用CMake进行交叉编译时,通常通过CMAKE_TOOLCHAIN_FILE
选项指定工具链文件。在GNU terminology中,可以使用此文件指定主机体系结构工具集。但是,通常不能指望能够执行使用此工具链构建的任何内容。通常,需要为构建体系结构编译一些构建工具。
请考虑以下设置。我有两个源文件genfoo.c
和bar.c
。在构建期间,需要编译和运行genfoo.c
。它的输出需要写入foo.h
。然后我可以编译bar.c
,其中#include "foo.h"
。由于CMake默认使用主机架构工具链,因此bar.c
的说明很简单。但是,我如何告诉它使用构建架构工具链来编译genfoo.c
?简单地说add_executable(genfoo genfoo.c)
将导致使用错误的编译器。
CMake一次只能处理一个编译器。所以 - 如果你没有很长的路要走,将其他编译器设置为一种新语言 - 你将最终得到两个配置周期。
我看到以下方法来自动执行此过程:
cmake_minimum_required(VERSION 3.0)
project(FooBarTest)
# When crosscompiling import the executable targets
if (CMAKE_CROSSCOMPILING)
set(IMPORT_PATH "IMPORTFILE-NOTFOUND" CACHE FILEPATH "Point it to the export file path from a native build")
file(TO_CMAKE_PATH "${IMPORT_PATH}" IMPORT_PATH_CMAKE)
include(${IMPORT_PATH_CMAKE}/genfooTargets.cmake)
# Then use the target name as COMMAND, CMake >= 2.6 knows how to handle this
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/foo.h
COMMAND genfoo
)
add_executable(bar bar.cpp ${CMAKE_CURRENT_BINARY_DIR}/foo.h)
target_include_directories(bar PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
endif()
# Only build the generator if not crosscompiling
if (NOT CMAKE_CROSSCOMPILING)
add_executable(genfoo genfoo.cpp)
export(TARGETS genfoo FILE "${CMAKE_CURRENT_BINARY_DIR}/genfooTargets.cmake")
endif()
然后使用如下脚本:
build.sh
#!/bin/bash
if [ ! -d hostBuild ]; then
cmake -E make_directory hostBuild
cmake -E chdir hostBuild cmake ..
fi
cmake --build hostBuild
if [ ! -d crossBuild ]; then
cmake -E make_directory crossBuild
cmake -E chdir crossBuild cmake .. -DIMPORT_PATH=${PWD}/hostBuild -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
fi
cmake --build crossBuild
我将通过调用./build.sh
获得所需的结果。CMakeLists.txt
甚至可能用我知道构建工具的输出路径的东西替换export()
/ include()
,例如通过使用CMAKE_RUNTIME_OUTPUT_DIRECTORY
将简化事情:
的CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(FooBarTest)
# Then use the target name as COMMAND. CMake >= 2.6 knows how to handle this
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/foo.h
COMMAND genfoo
)
add_executable(bar bar.cpp ${CMAKE_CURRENT_BINARY_DIR}/foo.h)
target_include_directories(bar PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
编译工具/的CMakeLists.txt
cmake_minimum_required(VERSION 3.0)
project(BuildTools)
add_executable(genfoo genfoo.cpp)
build.sh
#!/bin/bash
if [ ! -d crossBuild ]; then
cmake -E make_directory crossBuild
cmake -E chdir crossBuild cmake .. -DCMAKE_TOOLCHAIN_FILE=toolchain.cmake
fi
if [ ! -d hostBuild ]; then
cmake -E make_directory hostBuild
cmake -E chdir hostBuild cmake ../buildTools -DCMAKE_RUNTIME_OUTPUT_DIRECTORY:PATH=${PWD}/crossBuild
fi
cmake --build hostBuild
cmake --build crossBuild
参考